A standard one-piece spoked wheel rim comprises a center hub formed with lug holes for attachment to the vehicle, a plurality of spokes extending radially from the hub, and an outer ring on which the tire is mounted. Such a wheel hub is typically cast of an aluminum alloy and then machined to shine and smooth the spokes, to form accurate circular outer edges for holding the tire, and to provide accurately positioned and sized lug and valve holes.
While it has been suggested to use some automatic machining tools to do parts of the finish machining of such a workpiece, it is standard to do the final smoothing, the removal of parting lines from the mold, and all the boring in manual steps. Furthermore since the outer edges of the rim must be cut to very high tolerances, it is standard to mount the rim in a separate lathe that serves solely to perform this machining operation.